Pressure fluid control valve

ABSTRACT

The valve serves to control the supply of pressure fluid from a first tubular member constituting a pressure fluid outlet to a second tubular member which forms part of a pressure fluid consumer which is movable relative to said first tubular member between a first position more remote from said first tubular member and a second position nearer to said first tubular member. The valve comprises an inner sleeve secured to said second tubular member and an outer sleeve surrounding said inner sleeve and secured to said first tubular member. The inner and outer sleeves define together a flow path adapted to establish a communication between said first and second tubular members. A valve seat is secured to said outer sleeve and forms a frustoconical constriction in said flow path. A valve cone is disposed in said flow path on the side of said valve seat which is opposite to said inner sleeve and axially movable relative to said valve seat and adapted to sealingly engage the same. Said valve cone has an outside diameter which exceeds the inside diameter of said constriction. Spacing means are disposed between said valve cone and said inner sleeve and arranged to hold said valve cone clear of said valve seat unless said inner and outer sleeves are in a relative position corresponding to said second position of said second tubular member.

United States Patent 1 91 Primary Exami nerSam'uel Scott Attorney,Agent, or Firm-Arthur O. Klein Husz'ar 1 Feb. 26, 1974 [541 PRESSUREFLUID CONTROL vALvr: r [75] inventor: Josef Huszar, KapfenbergAustria[57] ABSTRACT [73] Assignee: Gebr. Boe hlel' & (30- AG, V en a, Thevalve serves to control the supply of pressure fluid v Austria fromafirst tubular member constituting a pressure fluid outlet to a secondtubular member which forms [22'] 1972 part of a pressure fluid consumerwhich is movable [21] Appl. No.: 277,382 relative to said first tubularmember between a first position more remote from said first tubularmember [30] Foreign Apbucafion Priority Data and a second positionnearer to said first tubular memher. The valve comprises an inner sleevesecured to Oct. 19, Austria s i Second tubular member n n Outer sleeve1' rounding said inner sleeve and securedto said first tu- [52] US. (ii.bular memben The inner and outer Sleeves define [51] 'l C 349 gether aflow path adapted to establish a communica- [58] meld oi cal-ch 3 f 3tion between said first and second tubular members. A valve seat issecured to said outer sleeve and forms a 1 frustoconical constriction insaid flow path. A valve [56] References cued cone is disposed in saidflow path on the side of said UNITED STATES PATENTS valve seat which isopposite to said inner sleeve and 2,906,493 9/1959 Whitener 251/346axially movable relative to said valve seat and adapted 2,121,268 6/1938Shaffer 251/346 to sealingly engage the same. Said valve cone has an2,944 793 1960 Conrad 251/34l X outside diameter which exceeds theinside diameter of 2,509,470 5/1950 Baker 251/347 d constriction Spacingmeans-are disposed between 2,553,991 g l said valve cone and said innersleeve and arranged to i 1011964 gf 251/351 hold said valve cone clearof said valve seat unless said 2:90l:0O1 Y 8/1959 1/349 X inner andouter sleeves are in a relative position corre- 3,667,505 6/1972 Radig251/315 x Spondmg to 8816 Second Position of Said Second tubular member;

6 Claims, 1 Drawing Figure PRESSURE FLUID CONTROL VALVE This inventionrelates to a valve for controlling the supply of pressure fluid to'apercussion drill, which valve is connected betw'een said drill and ahollow fitting, which drill and fitting are two members which arecapable of a limited relative displacement. When the percussion drillhas been retracted toward the fitting,

the housing of the apparatus bears on one of these relatively movablemembers and the valve member bears on the other of said members.

When a percussion drill is pulled out of the bore-hole or its cutter bitbreaks into a cavity when drilling, so-

called idle blows will be effected, in which the full .kinetic energy ofthe percussion piston acts on the holder for the cutter bit. If pressurefluid is supplied to the percussion drill, for these idle blows, therate of which is not much less than for normal working blows, the abovementioned holder often suffers damage after a relatively short operatingtime.

This disadvantage is allegedly avoided in a valve of the kind mentionedfirst hereinbefore in a prior art arrangement in which the valve member.has a headshaped portion, which together with a constriction in thehousing defines a throttling gap for the compressed air flowing to thepercussion drill when the percussion drill has been advanced relative tothe drill pipe, i.e., during the idle blows. The described valve has thedisadvantage that it is difficult in practice to provide a throttlinggap which is dimensioned so that blows are effected with the optimumforce.

It is an object of the invent-ion to avoid the stated disadvantages andto provide a valve which can easily be designed so that idle blows areeither avoided entirely or are effected under the force which is optimumfor the percussion drill concerned. In a valve of the kind the idlementioned first hereinbefore, this is accomplished according to theinvention in that the valve member is a valve cone, which has an outsidediameter that is larger than the inside diameter of the valve seat inthe housing and which is in sealing engagement with the valve seat whenthe percussion drill has been advanced from the fitting.

In a preferred embodiment of the apparatus according to the invention,relatively strong working blows but light idle blows are effectedbecause a duct is provided, which is connected in shunt to the valve gapand preferably consists of an axial bore in the valve cone.

An embodiment of the percussion drill according to the invention isshown by way of example in a diagrammatic longitudinal sectional view inthe single FIGURE of the drawing.

' body 7, which surrounds the spacer 2, and a connecting fitting 9,which is screwed to the valve body 7 and to an extension pipe 10 of thedrill pipe. The valve body 7 is provided with the conical valve seat 8which cooperates with the valve cone 3.'The outside diameter D of thevalve cone 3 exceeds the inside diameter d of the 2 valve seat 8. Toprevent the valve cone 3 from falling out of the valve when-thepercussion rill has been removed from the borehole and is turned upsidedown, a stop member 13 is secured, preferably pressed-in, in the fitting9. The cylinder 1 is connected to the valve body 7 by means of aretaining cap 11, which is secured to the cylinder and embraces a collar7, which is provided on the valve body 7. Because the distance betweenthe end face 1 of the cylinder 1 and the inwardly extending shoulder 11'of the retaining cap exceeds the axial length b of the collar 7, thecylinder 1 together with the spacer 2-secured to it is capable of a israised. I

body 7. The valve cone 3 is formed with an axial bore 6, which has adiameter d, that is smaller than the inside diameter d of the spacer 2.(Instead of that bore 6 in .the valve cone 3, a similar bore might beformed in the valve body 7). Only the last pipe section 10 of the drillpipe is shown on the drawing. The drill pipe is screwed to a rotatingmechanism, which is not shown and 'disposed outside the borehole. Bymeans of a feed motor, the rotating mechanism can be verticallyreciprocated along a guide. When the cutter bit is forced against thebottom of the borehole by the feed motor and the weight of the drillpipe, the endface 7" of the valve body 7 engages. the cylinder 1 of thepercussion drill, and the valve cone 3 is clear of the valve seat 8..

Under this condition, the compressed air which is supplied flows throughthe drill pipe, the fitting the gap 5 between the valve cone 3 and thevalve seat 8, the hollow spacer 2 and the bore 6 freely into thepercussion drill so that the piston thereof imparts heavy blows to thecutter bit. On the other hand, when the drill rod is raised by the feedmotor or when the cutter bit breaks into a cavity'during the drillingoperation, the percussion drill cylinder 1 will descend under the actionof gravity relative to the valvebody 7 and the compressed air which issupplied will force the valve cone 3 against the valve seat 8 becausethere is a difference between the pressure forces acting on the two endsof the valve cone.- This position isv indicated in dash-dot lines. Theguide webs 4 are now clear of the spacer 2, and compressed air flows tothe percussion drill only through the axial bore 6 in the valve cone 3sothat the flow of compressive air is strongly throttled. Asa result,the piston of the percussion drill applies only light idle blows to thecutter bit so that a seizing on the wall of v the borehole will bereliably prevented as the drill pipe It is apparent that the valveaccording to the invention enables an operation of percussiondrills'with-compressed air which is under a much higher pressure thanthe air previously'used in such drills so that when other conditions arethe same the use of this valve enables a much higher percussion anddrilling performance tha with the previously known arrangements.

Although the invention is illustrated and described with reference toone preferred embodiment thereof, it is to be expressly understood thatit is in no way limited to the disclosure-of such a preferredembodiment, but

of the appended claims.

I claim:

1. A valve for controlling the supply of pressure fluid from a firsttubular member constituting a pressure fluid outlet to a second tubularmember forming part of a pressure fluid consumer and movable relative tosaid first tubular member between a first position more remote from saidfirst tubular member and a second position nearer to said first tubularmember, which valve comprises an inner sleeve coaxially secured to saidsecond tubular member,

w an outer sleeve surrounding said inner sleeve and coaxially secured tosaid first tubular member,

said inner and outer sleeves defining together a flow path to establisha communication between said first and second tubular members,

a valve seat secured to said outer sleeve and forming a frustoconicalconstriction in said flow path,

a valve cone disposed in said flow path on the side of said valve seatwhich is opposite to said inner sleeve and axially movable relative tosaid valve seat and adapted to sealingly engage the same, said valvecone having an outside diameter which exceeds the inside diameter ofsaid constriction and spacing means disposed between said valve cone andsaid inner sleeve and arranged to hold said valve cone clear of saidvalve seat unless said inner and outer sleeves are in a relativeposition corresponding to said second position of said second tubularmember in which said valve cone sealingly engages said seat.

2. A valve as set forth in claim 1, in which said outer sleeve issecured to a first tubular member consisting of a fitting and said innersleeve is secured to a second tubular member forming part of areciprocating motor of 5. A valve as set forth in claim 1, in which saidspac- I ing means comprise guide webs which are secured to said valvecone and extend in and are in slidable engagement with said outersleeve.

6. A valve as set forth in claim 5, which comprises a collar mounted onthe outside of said outer sleeve and a retaining cap having an internalshoulder surroundingsaid outer sleeve and adapted to be secured to saidsecond tubular member in such a position that said collar is disposedbetween said internal shoulder and said second tubular member and theaxial distance between said internal shoulder and said second tubularmember exceeds the axial length of said collar,

said collar having an outside diameter which exceeds the inside diameterof said shoulder and of said second tubular member and is adapted toengage said shoulder to define said first position and to engage saidsecond tubular member to define said second position of said secondtubular member.

1. A valve for controlling the supply of pressure fluid from a firsttubular member constituting a pressure fluid outlet to a second tubularmember forming part of a pressure fluid consumer and movable relative tosaid first tubular member between a first position more remote from saidfirst tubular member and a second position nearer to said first tubularmember, which valve comprises an inner sleeve coaxially secured to saidsecond tubular member, an outer sleeve surrounding said inner sleeve andcoaxially secured to said first tubular member, said inner and outersleeves defining together a flow path to establish a communicationbetween said first and second tubular members, a valve seat secured tosaid outer sleeve and forming a frustoconical constriction in said flowpath, a valve cone disposed in said flow path on the side of said valveseat which is opposite to said inner sleeve and axially movable relativeto said valve seat and adapted to sealingly engage the same, said valvecone having an outside diameter which exceeds the inside diameter ofsaid constriction and spacing means disposed between said valve cone andsaid inner sleeve and arranged to hold said valve cone clear of saidvalve seat unless said inner and outer sleeves are in a relativeposition corresponding to said second position of said second tubularmember in which said valve cone sealingly engages said seat.
 2. A valveas set forth in claim 1, in which said outer sleeve is secured to afirst tubular member consisting of a fitting and said inner sleeve issecured to a second tubular member forming part of a reciprocating motorof a percussion drill and said inner and outer sleeves are arranged toassume said first position when said motor is operating under a load andto assume said second position when said motor is operatingsubstantially under no load.
 3. A valve as set forth in claim 1, whichcomprises a duct, which by-passes said constriction and which is openwhen said valve cone sealingly engages said valve seat.
 4. A valve asset forth in claim 3, in which said duct is formed by a central axialbore in said valve cone.
 5. A valve as set forth in claim 1, in whichsaid spacing means comprise guide webs which are secured to said valvecone and extend in and are in slidable engagement with said outersleeve.
 6. A valve as set forth in claim 5, which comprises a collarmounted on the outside of said outer sleeve and a retaining cap havingan internal shoulder surrounding said outer sleeve and adapted to besecured to said second tubular member in such a position that saidcollar is disposed between said internal shoulder and said secondtubular member and the axial distance between said internal shoulder andsaid second tubular member exceeds the axial length of said collar, saidcollar having an outside diameter which exceeds the inside diameter ofsaid shoulder and of said second tubuLar member and is adapted to engagesaid shoulder to define said first position and to engage said secondtubular member to define said second position of said second tubularmember.